10139 smatch fixes for usr/src/cmd/stat

@@ -456,11 +456,11 @@
                 pos = iodevs;
                 while (pos && nr_iodevs) {
                         tmp = pos;
                         pos = pos->is_next;
 
-                        if (df && df->if_skip_floppy &&
+                        if (df->if_skip_floppy &&
                             strncmp(tmp->is_name, "fd", 2) == 0)
                                 continue;
 
                         list_del(&iodevs, tmp);
                         insert_iodev(ss, tmp);